Its mounted on the side of the motor all the way to the back under the intake manifold.
This is not a good pic,
You should also change all the hoses, hose number 3 connects to the back of the valve cover, they are brittle plastic hoses and always break, when the dealer did my valve ticking recall and removed the valve cover they didn't replace the hose, Im certain they messed it up.
The oil separator is 60-70ish, hoses are 40-50 ish a piece for the 3 you need.
It's not difficult to do once the manifold is off, my bentley manual suggests its possible to replace it without removing the manifold by removing the air filter housing and attacking it at that angle.
Gotta pay to play.
WTB LUX 5.0+